Ozonation of humic and fulvic acids in aqueous solutions and in the presence of H2O2 was studied at ozone doses of 33, 38 and 47 mg/l. Chemical oxygen demand (COD) and total organic compounds (TOC) of these compounds were tested. It was found that COD and TOC can be removed effectively by ozonation in the presence of H2O2. At 0.78 mg O-3/mg COT and 0.088 H2O2/O-3, about 94% COD and 38% TOC were eliminated in 30 min; at 1.35 mg O-3/MgCOT and 0.04 H2O2/O-3, about 88% COD and 68% COT were eliminated in 30 min; and at 1.92 mgO(3)/mgCOT and 0.61 H2O2/O-3, about 79% COD and 75% COT were eliminated in 30 min.